Minimally invasive surgical techniques such as endoscopies and laparoscopies are often preferred over traditional open surgeries because the recovery time, pain, and surgery-related complications are typically less with minimally invasive surgical techniques. In many laparoscopic procedures, the abdominal cavity is insufflated with carbon dioxide gas to a pressure of approximately 15 mm Hg. The abdominal wall is pierced and a cannula or trocar that is approximately 5 to 10 mm in diameter is inserted into the abdominal cavity. Typically multiple cannulas or trocars are inserted and placed at the surgical site so multiple instruments, such as laparoscopic telescopes, graspers, dissectors, scissors, retractors, etc., can be used at the same time. While miniaturized versions of laparoscopic procedures have also been developed, the instruments for such procedures are generally more expensive and fragile, and still typically require the use of multiple instruments or channels that have diameters of about 2 to 3 mm.
Because of the rise in popularity of minimally invasive surgeries, there has been significant development with respect to the procedures and the instruments used in such procedures. For example, in some procedures a single incision at the navel can be sufficient to provide access to a surgical site. This is because the umbilicus can be a preferred way to access an abdominal cavity in a laparoscopic procedure. The umbilical incision can be easily enlarged without significantly compromising cosmesis and without significantly increasing the chances of wound complications, thus allowing multiple instruments to be introduced through a single incision. However, a “chopstick” effect can occur which causes interference between the surgeon's hands and the instruments. This interference greatly reduces the surgeon's ability to perform a desired procedure.
Some surgical access devices have been developed to try and reduce the “chopstick effect.” For example, a device can include a chamber having a plurality of separate sealing channels that are configured to access a surgical location. Each sealing channel can be configured to receive an instrument and can seal the outside environment from the surgical location. Current devices designed to alleviate the “chopstick effect,” however, have their own unique problems. The configurations of these assemblies can lead to problems such as tissue collapsing around channels formed in the cannula. For example, the fascia layer of the abdomen can collapse around the channels when the cannula is used in conjunction with an abdominal procedure. The channels can be working channels in which instruments are often disposed, and thus the collapsed tissue can restrict and inhibit independent motion of the instruments disposed in the cannula. This problem is often exacerbated as the number of instruments disposed through the cannula increases.
Further, because insufflation is generally used as part of laparoscopic procedures, a resulting force is applied to the cannula that causes the cannula to be undesirably pushed in a direction out of a body, like a cork in a pressurized liquid bottle. While the assemblies can generally be sutured in place, the retention and stability capabilities of such assemblies are weak. Additionally, because the cannula is sutured to the tissue, removing the cannula during the course of the surgical procedure is both difficult and inconvenient. Thus, a surgeon is typically unable to easily remove objects from the surgical site or to use different types of cannulas during a single procedure.
Accordingly, there is a need for improved methods and devices for accessing a surgical site during a laparoscopic procedure. There is additionally a need for procedures and devices that allow for a cannula to be easily removed from a surgical site and replaced or reattached during a surgical procedure.